Tread and off-tread brake



Oct. 26, 1954 c. E. TACK TREAD AND OFF-TREAD BRAKE 2 Sheets-Sheet 1 Filed Jan. 10, 1951 i 4; gwz

Oct, 26, 1954 c. E. TACK 2,692,659

TREAD AND OFF-TREAD BRAKE Filed Jan. 10, 1951 2 Sheets-Sheet 2 INVENTOR. E Zea 5;

Patented Oct. 26, 1954 TREAD AND OFF-TREAD BRAKE Carl E. Tack, Chicago, Ill., assignor to American Steel Foundries, Chicago, 111., a corporation of New Jersey Application January 10, 1951, Serial No. 205,317

12 Claims. 1 This invention relates to railway brake equipment.

A general object of the invention is to provide such a combination brake wherein the tread brakes may have metal to metal contact such as cast iron shoes engaging the wheels and the off wheel brake may have composition shoes engaging a friction disk rotatable with the wheel. Such an arrangement admits a stabilized braking action throughout the entire range of railway speeds.

Another object of the invention is to devise a novel combination brake package which may be readily applied and removed from a conventional railway car truck.

A more specific object of the invention is to provide an arrangement wherein the brake system is so connected to the sprung and unsprung parts of the railway truck that relative movement between the sprung and unsprung parts is readily accommodated and wherein a novel guiding arrangement is provided to maintain the brake parts in operative alignment with the wheel and the disk.

A still further object of the invention is to provide a simplified guiding arrangement for the brake package to maintain the package in a substantially horizontal position during vertical movements of the package.

These and other objects of the invention will become more apparent from the specification and the drawings, wherein:

Figure 1 is a top plan view of one quarter of a railway car truck incorporating the invention;

Figure 2 is a side elevational view thereof;

Figure 3 is a sectional view taken substantially on the line 3-3 of Figure 1; and

Figure 4 is a horizontal sectional view through the rotor brake assembly.

Describing the invention in detail, the railway car truck compresses a conventional frame 2 including a side rail 4 at each side thereof, the side rails being connected at each end of the frame by an end rail 6 and intermediate their ends by a transom 8 adjacent each end rail. The transoms afford the usual support for a bolster which carries a car body (not shown).

Each side rail t comprises a pair of depending pedestals Ill, Ill at each end thereof between which is fitted a journal box l2 shown in phantom lines in Figure 2, the journal box forming the usual means of connection for an associated wheel and axle assembly I4 which includes an axle Ni with a wheel It at each end thereof, the wheel being connected at its hub portion to a brake rotor 26 which is disposed inboardly of the wheel. It will be noted that the frame 2 is a sprung member and is supported adjacent each end of each side thereof by means of a plurality of springs 22 (Figure 3) which at their upper ends fit into pockets 24 on the underside of the side rail 4. The lower ends of the springs 22 seat within spring seats 26 fastened in any convenient manner as is conventional practice to an equalizer 28, seated at opposite ends on the journal boxes l2 in usual manner.

A primary feature of the invention is the provision of an articulated connection between a brake and the sprung frame member 2, wherein the brake is partially supported from the frame member and partially from the wheel and axle assembly I l.

The brake arrangement comprises a package generally designated 30, said package including integral housings 34 and 36 affording a support for a rotor brake assembly and a tread brake assembly, respectively, as hereinafter described. The housing 34 is of box-section and comprises spaced top and bottom walls 38 and 40 (Figure 3) inboard and outboard Walls 42 and 44 and a rear wall 46 (Figure 4) The space within the casing 34 is divided by an intermediate wall 48. Rearwardly of wall 48 is positioned a cylinder 50 with pistons 52 projecting from opposite ends. The cylinder 50 is provided with a series of threaded openings 54, 54 into which may be threaded studs 56, 56 (Figure 1) which may secure the cylinder to a cover plate 58 which may be mounted on the top of the casing 34 and secured thereto as by studs 6U, 66. The cover plate may be provided with the usual pipe fitting 62 which may communicate with a complementary opening 64 (Figure 4;) in the cylinder 50 to admit actuating fluid into the cylinder.

The rotor brake actuating unit comprising the pistons 52 and the cylinder 50 is received between a pair of brake levers 6'5, 66. The inner ends of the levers 66, 66 bear as at 68, '58 (Figure 4) against the pistons 52, 52. The levers 66, 66 are pivoted intermediate their ends as at l0, ID to opposite ends of a fulcrum block 12 which in turn may be pivoted to wall 48 of the casing and a front cover plate 14 as at 16 and 18 respectively, on a substantially horizontal axis extending longitudinally of the truck. The outer ends of the levers 6'6, 66 project through the cover plate 14 and at their outer extremities are provided with brake head and shoe assemblies 80, which are pivoted to the respective levers on substantially vertical axes by bolt and nut assemblies 82, 82. A brake head balancing device 83 is provided for each head. Bellows 84, 8A are secured around the levers and close the openings through the cover plate It and provide dust seals. The levers 66, 66 are connected as at 36, 86 at points inwardly of the pivot l9, 19 to opposite ends of a tension release spring 88 which is arranged to rotate the levers to positions disengaging the brake head and shoe assemblies 80, 80 from the rotor. It will be seen that the brake head and shoe assemblies 80 are disposed at opposite sides of the adjacent rotor 20.

The outboard wall 44 of the casing 34 is formed integral with the inboard side of the casing 38. The casing 30 and the wheel tread brake may be identical with that shown in my Patent No. 2,580,940, dated February 5, 1952.

In view of the showing in my said patent the arrangement within the casing 30 is not shown and will not be described in detail. Sufiice it to say that the lever 90 extends through the bottom of the casing 36 adjacent the related wheel I and pivotally carries at its lower end as at 82 a brake head and shoe assembly of conventional design including a brake head 94 with a shoe 06 arranged to engage the tread of the wheel I8. A conventional balancing device 98 is utilized to maintain the position of the brake head and shoe assembly concentric with the wheel I8. The lever 90 is actuated by an independent cylinder device I00 which operates through a rack and pinion arrangement, as shown in said copending application, to rotate the lever 00 to release and applied position.

The brake package 30 is afiorded a novel support from the truck frame which comprises a parallelogram linkage at the inboard side of the package including a top lever I02 which at one end is made an integral part of a tube constituting a fulcrum or pivot member I04 as by welding at I08. The other end of the link I02 is pivotally connected as at I00 to the upper end of a vertical link or lever H0, the lower end of the link H0 being pivoted as at H2 to one end of a link or lever I I4, the link I I4 extending beneath the link III-2 and having its other end pivoted as at H5 to a bracket H8 which may be formed as an integral part of the adjacent transom 8 or suitably secured thereto in any convenient manner as by bolts H9, H0. The lever H0 is fixed on its outboard side intermediate its ends with the inboard side of the casing 34, preferably as by welding at I2I, to the external side of the inboard wall 42 of the casing 34.

The pivot member I04 is received intermediate its ends within a clamp I20, said clamp having a bottom portion I22 (Figure 3) which may be formed integral with the adjacent transom 3 or suitably secured thereto as by bolts I24, I24 and having a top clamping member I20 which may be secured to the bottom member as by bolt and nut assemblies I28, I28. A rubber or other resilient bushing I 20 may be positioned in the clamp around the member I04 to provide a tight rattlefree rotatable connection. The outboard extremity of the fulcrum member I04 may be connected to the inner end of a torque arm I30 as may be readily seen in Figures 1 and 3. The instant connection is best adapted by means of a plate I82 which may be welded to the outboard end of member I04 as at I34 and to the inner end of the torque arm as at I36. arm I30 is disposed outboardly of the package and may be pivoted intermediate its ends to the outboard side of the casing 34 by means of a stud I38. The outer end of the torque arm may have a flexible or movable connection as at I40 with a bracket I44 which may afford a seat for the adjacent end of the equalizer 28. The bracket I44 and its arrangement with the journal box and equalizer may be conventional as will be readily understood by those skilled in the art.

The torque The torque arm I30, plate I32, fulcrum member I04, and link I02 are rigidly connected, as hereinbefore mentioned, to form a yoke or U-shaped member offering suspension support for the braking member.

In operation and referring first to Figure 4, actuation of pistons 52 causes the levers 66, B0 to rotate in such manner as to engage the friction shoes or stators 80, with opposite sides of the brake rotor 20'. Simultaneously the wheel tread brake is actuated so that the shoe is engaged with the tread of the wheel I8. During vertical movements of the truck frame with respect to the wheel and axle assembly, the brake package is maintained in a predetermined position inasmuch as the pivot member I04 will rotate within the clamp and at the same time the levers I02 and I I0 will have relative pivotal movement at I08 and the levers H0 and I I4 will have relative pivotal movement at H2 and the lever I I4 will have pivotal movement relative to the truck frame at H6. It will be seen that the parallelogram linkage comprising the levers I02, H0 and H4 will maintain the package in a predetermined vertical plane and that during relative vertical movements between the truck frame and the upsprung portions of the truck, the pivot member I04 is rotated by rotation of the torque arm I30 at I38 whereby the arm or lever I02 is rotated so that opposite sides of the brake means are raised or lowered simultaneously and vertical movements are guided by the parallelogram linkage comprising the members I02, I I0 and I I4.

It may be noted that the points of pivot I38 and I08 are coaxial and that the radial distance from the axis of member I04 to the axis of pivot I08 and I38 is the same as the distance between points of pivot H2 and H5 of the guide link H4. Furthermore, in normal position the links H4 and I02 and arm I30 extend generally horizontally so that the distance from the points of pivot with the frame to the points of pivot with the brake means is farthest longitudinally of the truck when the links and arm are horizontal. This feature prevents excessive movements of the brake means toward or away from the friction member or rotor 20.

I claim:

1. In a brake arrangement for a railway car truck comprising a frame, a wheel and axle assembly, a brake rotor on the assembly, said frame comprising a transom extending transversely of the truck, a support pivoted to the transom on a substantially horizontal axis extending transversely of the truck, said support having spaced portions extending in adjacent relationship from opposite ends of the axis of pivot, one of said portions having its outer extremity supported on said assembly, brake means for the rotor and at least one wheel of the assembly pivotally connected to each portion on an axis extending sub stantially parallel to the first-mentioned axis, and a link spaced vertically from one of said portions and pivotally connected at opposite ends to said transom and said brake means on axes parallel to the other of said axes, the distance between the axes of pivot of the link being substantially equal to the distance between the axis of pivot of the support and the axis of pivot of the brake means.

2. In a brake arrangement for a railway car truck comprising a frame and a wheel and axle assembly, combination tread and off-wheel brake means cooperatively associated with the assembly, and means for suspending said brake means in predetermined relationship with said wheel and axle assembly and comprising a substantially vertical member connected to the inboard side of said brake means, links connected at corresponding ends thereof to respective ends of said vertical member, one link having a pivotal connection at the other end to the frame, a pivot member pivoted to the frame and having one end fixedly connected to the other end of the other link, a torque arm pivoted intermediate said ends to the outboard side of said brake means and fixedly connected at one end to the other end of said pivot member, said arm having its other end flexibly connected to the wheel and axle assembly, the axes of pivot at all of the pivot points being substantially parallel.

3. In a brake arrangement for a railway car truck comprising sprung and unsprung portions movable generally vertically with respect to each other, said unsprung portion comprising a wheel and axle assembly and including an oiT-wheel braking surface, tread and off-wheel brake means associated with a wheel and said surface respec tively and a variable parallelogram support suspending said brake means from the sprung portion and including a member contacting at one point said assembly and movably connected at another point to said sprung portion and pivotally connected elsewhere to said brake means, said support accommodating relative vertical movement between the sprung and unsprung portions while maintaining said brake means in a substantially fixed position relative to said wheel and surface.

4. In a brake arrangement for a railway car truck comprising a frame and a wheel and axle assembly, a U-shaped structure comprising spaced legs and an intermediate pivot member, means flexibly and pivotally connecting said pivot member to said frame, a movable connection between one of said legs and said assembly and brake means pivotally carried between said legs and cooperatively associated with said assembly.

5. A suspension yoke for a railway brake comprising spaced arms arranged in adjacent substantially parallel relationship, and a pivot element interconnecting adjacent ends of said arms, one of said arms being shorter than the other and having a pivot point at its other end, and a pivot point on the other arm intermediate its ends.

6. In a brake arrangement for a railway car truck, a frame and a wheel and axle assembly, a support at one side of the assembly, wheel tread and off-wheel brakes carried solely by said support, a torque arm at the outboard side of the support and pivoted intermediate its ends thereto and flexibly connected at one end to said assembly, a horizontal pivot element connected at its outboard end to the other end of said arm, a clamp on the frame surrounding said element, a flexible bushing compressed between said clamp and element, a horizontal link having one end connected to the other end of said element, a vertical lever rigidly connected intermediate its ends to the inboard side of said support, a pivotal connection between the other end of the link and the upper end of the lever, and a horizontal guide having one end pivoted to the lower end of the lever and the other end to the frame.

'7. In a railway car truck brake arrangement comprising a wheel and axle assembly, said assembly supporting an unsprung member with a sprung frame member supported thereon; the combination of brake means, an actuating arm supported by and operatively engaging said assembly and offering pivotal support for said brake means, a linkage arrangement rigidly connected to said actuating arm and pivotally connected to said frame member and brake means, and operative to prevent substantial tipping of said brake means relative to the horizontal plane of said truck.

8. In a railway car truck brake arrangement comprising a wheel member and axle assembly supporting an unsprung frame, and a sprung frame supported thereon; the combination of a braking member on said assembly and inboard of said wheel, off-wheel brake means engaging said braking member, tread brake means engaging said wheel member, guide means supporting both of said brake means, said guide means forming a linkage parallelogram rigidly secured to said brake means and pivotally secured to said sprung frame and assembly and operative to maintain a predetermined alignment between the engaging means and members.

9. In a brake arrangement for a railway car truck comprising an unsprun frame supported by a wheel and axle assembly, a sprung frame supported by said unsprung frame; the combina tion of tread and off-tread brake means, a single housing to support said brake means, a yoke having a pair of substantially parallel arms interconnected at common ends thereof, said yoke having pivotal connection to said sprung frame intermediate said arms, said arms arranged to embrace said housing and have pivotal connection thereto, and one of said arms being movably supported by said wheel and axle assembly.

10. A brake arrangement, according to claim 9, wherein a substantially vertical link is secured to said brake means; another link disposed horizontally is pivotally secured at one end to the frame and at the other end to one end of said vertical link; said yoke having pivotal connection to the opposite end of said vertical link at an extremity of one of said arms; the yoke, the vertical link, and the horizontal link, defining with the frame a parallelogram linkage for guiding vertical movement of said brake means.

11. As an article of manufacture, a supporting yoke for a railway brake comprising a pair of spaced coplanar arms, a pivotal member connecting the adjacent end of said arms, one of said arms being shorter than the other and the distance between said arms being less than the length of the longer arm, pivot means on the unconnected end of the shorter arm, and other pivot means on the longer of said arms intermediate the ends thereof and coaxial with the first mentioned pivot means.

12. As an article of manufacture, a brake package housing comprising a pair of adjacent integrally formed sections and means to support in the respective sections tread and off-wheel braking mechanisms, and a member fixed. to one side of said housing, pivot means at opposite ends of said member for mounting same, and pivot means on the opposite side of the housing coaxial with the first mentioned pivot means.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,236,898 Eksergian Apr. 1, 1941 2,284,484 Eksergian May 26, 1942 2,359,806 Tack Oct. 10, 1944 2,412,431 Tack et al. Dec. 10, 1946 2,416,869 Eksergian Mar. 4, 1947 2,584,940 Tack Feb. 5, 1952 

